This invention relates to novel carbacyclin derivatives, a process for their preparation, as well as their use as medicinal agents.
The precursor of carbacyclins, prostacyclin, was isolated in 1976. Its structure was clarified in the same year (Postaglandins 12 : 915, 1976). For some time, as a prostaglandin abbreviation, the designation PGI.sub.2 has become accepted for prostacyclin. Correspondingly, carbacyclins are also called 6a-carbaprostaglandins I.sub.2.
The nomenclature of the compounds of this invention is based on a proposal by Morton and Brokaw (J. Org. Chem. 44 : 2280 [1979]). The synthesis of these compounds in all cases yields two double-bond isomers characterized by the symbols (5E) or (5Z).
Based on their biological and pharmacological properties, prostacyclins and their analogs are suitable for therapy and prophylaxis of thromboses, infarctions, and other cardiovascular diseases. The duration of activity of these compounds is frequently still too brief for therapeutic purposes. For this reason, all structural modifications of known PGI.sub.2 derivatives pursue the objective of prolonging the period of efficacy, increasing the selectivity of activity, and simultaneously reducing the effective dose.